Amphiphilic polymer

ABSTRACT

The present application relates to an amphiphilic polymer and a method of preparing the same. 
     Furthermore, the present application relates to a micelle including a drug encapsulated by the amphiphilic polymer and a composition including the same. 
     The amphiphilic polymer according to the present application has excellent drug encapsulation properties as well as good dispersion properties in an aqueous solution.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2015-0165873, filed on Nov. 25, 2015, the disclosureof which is incorporated herein by reference in its entirety.

BACKGROUND 1. Field of the Invention

The present application relates to an amphiphilic polymer, a method ofpreparing the same, a micelle including the amphiphilic polymer and acomposition thereof.

2. Discussion of Related Art

In the fields of pharmaceuticals and cosmetics, there has been a need todevelop a formulation capable of stably loading various materials whichare effective for skin into a product as well as enhancing the conditionof the skin by effectively acting on the skin.

However, most drugs combine or react with other materials because ofinsolubility or instability, thus destabilizing the entire system.

Accordingly, various technologies for loading an effective drug morestably and easily into a formulation have been developed, and examplesof the technologies include nanoemulsions prepared by forming emulsionparticles into nano-scale particles, liposomes prepared by theself-assembly properties of phospholipids, solid lipid nanoparticlesobtained by forming a solid lipid into nanoparticles, polymernanoparticles with an interface stabilized by a surfactant, etc.

However, these nanoparticles also have many problems from the viewpointof the insolubility problem of a target drug and the improvement of thepercutaneous absorption effect according to dispersion properties.

RELATED ART DOCUMENT

(Patent Document) JP Laid-open Patent Publication No. 2009-155282

SUMMARY OF THE INVENTION

The present application provides an amphiphilic polymer capable ofeffectively encapsulating a drug as well as having excellent dispersionproperties, and a method of preparing the same.

Furthermore, the present application provides a micelle including anamphiphilic polymer which is effectively dispersed in water or oil andis capable of exhibiting excellent percutaneous absorption properties,and a composition including the micelle.

The present application relates to an amphiphilic polymer and a micelle.The micelle includes a drug encapsulated by an amphiphilic polymer.

The amphiphilic polymer according to the present application is atriblock copolymer which can exhibit phase separation properties, andeffectively encapsulates a drug by self-assembly properties thereof, andcan also be included in the pharmaceutical composition or cosmeticcomposition while having excellent dispersion properties.

In the present application, the term “amphiphilic polymer” may refer toa polymer having regions with different physical properties, forexample, different solubility parameters, and an example thereof may bea polymer including both a hydrophobic region and a hydrophobic region.

In the present application, the term “hydrophilic or hydrophobic region”refers to a region, for example, which is included in a polymer whileforming a block, in a state in which each region can be determined to bephase-separated, and the extent of hydrophilicity or hydrophobicity ofeach region is relative.

In the present application, the term “self-assembly properties” refersto a phenomenon in which an amphiphilic polymer spontaneously causesfine phase separation in a solution to have regularity and uniformity insize.

The amphiphilic polymer according to the present application includes afirst block (A) and a second block (B) which is phase-separated from thefirst block (A). Moreover, the second block (B) includes apolymerization unit (B1) of an acrylic monomer or vinyl-based monomer ofwhich a homopolymer has a solubility parameter of less than 10.0(cal/cm³)^(1/2) and a polymerization unit (B2) of a polymerizablemonomer having a functional group which is capable of forming a hydrogenbond.

The amphiphilic polymer according to the present application includestwo blocks that are phase-separated from one another while having apolymerization unit of a polymerizable monomer having a functional groupat a hydrophobic region, and thus has a remarkable drug loadingcapability to achieve stability of a micelle.

In the present application, the term “phase-separated from each other”denotes a state in which the first block and the second block are notmixed with each other, and form their own blocks when no external actionis applied.

The amphiphilic polymer according to the present application includesthe first block (A) and the second block (B) which is phase-separatedfrom the first block (A).

The first block (A) refers to a hydrophobic region of the amphiphilicpolymer, and for example, may include a polymer with a solubilityparameter of 10 (cal/cm³)^(1/2) or more.

A calculation method of the solubility parameter is not particularlylimited, and may follow methods known in the art. For example, theparameter may be calculated or obtained using a method known in thefield as a Hansen solubility parameter (HSP).

In another embodiment, the first block (A) may include a polymer havinga solubility parameter of 13 (cal/cm³)^(1/2) or more, 14 (cal/cm³)^(1/2)or more, 15 (cal/cm³)^(1/2) or more, 16 (cal/cm³) ^(1/2) or more or 17(cal/cm³) ^(1/2) or more. The upper limit of the solubility parameter ofthe first block (A) is not particularly limited, and for example, may be25 (cal/cm³)^(1/2) or less, or 23 (cal/cm³)^(1/2) or less.

The first block (A) may include any known polymer as long as the polymersatisfies the aforementioned solubility parameter and is capable offorming a hydrophobic region of the amphiphilic polymer which can load adrug according to the present application.

In an embodiment, the first block (A) may be one or more selected fromthe group consisting of a polyethylene glycol, a polyethyleneglycol-propylene glycol copolymer, a polyvinylpyrrolidone and apolyethyleneimine.

Specifically, the first block (A) may be, but is not limited to, apolyethylene glycol having a number average molecular weight in therange of 500 to 100,000. In the present application, the term “numberaverage molecular weight” may refer to an analysis numeric valuemeasured by a nuclear magnetic resonator (NMR). Unless otherwisedefined, the molecular weight of a polymer may denote the number averagemolecular weight of the polymer.

The second block (B) includes a polymerization unit (B1) of an acrylicmonomer or vinyl-based monomer of which a homopolymer has a solubilityparameter of less than 10.0 (cal/cm³)^(1/2) and a polymerization unit(B2) of a polymerizable monomer having a functional group which iscapable of forming a hydrogen bond.

In the present application, the term “acrylic monomer” refers to(meth)acrylic acid or a derivative thereof. Furthermore, the term“(meth)acrylic acid” denotes acrylic acid or methacrylic acid.

As will be described below, the second block (B) of the amphiphilicpolymer according to the present application is a portion that isadjacent to a drug to surround the drug and serves to form the overallshape of a micelle.

Consequently, the second block (B) denotes a relatively hydrophobicportion in the amphiphilic polymer, and includes a polymerization unit(B1) of an acrylic monomer or vinyl-based monomer of which a homopolymerhas a solubility parameter of less than 10.0 (cal/cm³)^(1/2) and apolymerization unit (B2) of a polymerizable monomer having a functionalgroup which is capable of forming a hydrogen bond.

In another embodiment, the second block (B) may include a polymerizationunit (B1) of an acrylic monomer or vinyl-based monomer of which ahomopolymer has a solubility parameter of less than 9.8 (cal/cm³)^(1/2)or less than 9.5 (cal/cm³)^(1/2). The lower limit of the solubilityparameter of the acrylic monomer or vinyl-based monomer is notparticularly limited, and for example, may be 2 (cal/cm³)^(1/2) or more,or 4 (cal/cm³)^(1/2) or more.

An example of the acrylic monomer may be a compound represented by thefollowing Formula 1 or 2, but is not limited thereto.

In Formulas 1 and 2, Q is hydrogen or an alkyl group, in Formula 1, B isa linear or branched alkyl group with one or more carbon atoms, analicyclic hydrocarbon group, an aromatic substituent or a carboxylgroup, and in Formula 2, R₁ and R₂ each independently representhydrogen, a linear or branched alkyl group with one or more carbonatoms, an alicyclic hydrocarbon group, or an aromatic substituent.

In Formulas 1 and 2, an alkyl group existing at Q may be an alkyl grouphaving 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms,1 to 8 carbon atoms or 1 to 4 carbon atoms. The alkyl group may be alinear, branched or cyclic alkyl group. Furthermore, the alkyl group maybe optionally substituted with one or more substituents.

In Formulas 1 and 2, B, R₁ and R₂ may each independently represent alinear or branched alkyl group with 1 or more, 3 or more, 5 or more, 7or more or 9 or more carbon atoms, and may be optionally substituted orunsubstituted. Such a compound having a relatively long-chain alkylgroup is known as a hydrophobic compound. The upper limit of the numberof carbon atoms of the linear or branched alkyl group is notparticularly limited, and for example, the alkyl group may be an alkylgroup with 20 or fewer carbon atoms.

In another embodiment, in Formulas 1 and 2, B, R₁ and R₂ may be analicyclic hydrocarbon group, for example, an alicyclic hydrocarbon groupwith 3 to 20, 3 to 16 or 6 to 12 carbon atoms, and an example of thehydrocarbon group includes an alicyclic alkyl group with 3 to 20, 3 to16 or 6 to 12 carbon atoms, such as a cyclohexyl group, an isobornylgroup, etc. Such a compound having an alicyclic hydrocarbon group isalso known as a relatively hydrophobic compound.

In another embodiment, in Formulas 1 and 2, B, R₁ and R₂ may be anaromatic substituent such as an aryl group, an aryl alkyl group, etc.

In the above description, the aryl group may be, for example, an arylgroup with 6 to 24, 6 to 18 or 6 to 12 carbon atoms. Further, the alkylgroup of the aryl alkyl group may be, for example, an alkyl group with 1to 20, 1 to 16, 1 to 12, 1 to 8 or 1 to 4 carbon atoms. An example ofthe aryl group or the aryl alkyl group includes a phenyl group, aphenylethyl group, a phenylpropyl group, a naphthyl group or the like,but is not limited thereto.

In the present application, examples of the substituent which mayoptionally substitute an alkyl group, an aryl group, a hydrocarbon groupor the like in Formulas 1 and 2 include a halogen such as chlorine orfluorine, a glycidyl group, an epoxy group such as an epoxy alkyl group,a glycidoxy alkyl group or an alicyclic epoxy group, an acryloyl group,a methacryloyl group, an isocyanate group, a thiol group, an alkylgroup, an alkenyl group, an alkynyl group, an aryl group or the like,but are not limited thereto.

The compound represented by Formula 1 may be, for example, an alkyl(meth)acrylate. In the above description, the term “(meth)acrylate”refers to acrylate or methacrylate. Examples of the alkyl (meth)acrylateinclude methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl(meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate,t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate,hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylbutyl(meth)acrylate, n-octyl (meth)acrylate, isobornyl (meth)acrylate,isooctyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylateor the like, but are not limited thereto.

In the present application, a suitable monomer among the monomersdescribed above may be used in consideration of the desired physicalproperties of the amphiphilic polymer.

In an embodiment, in Formula 1, Q may be hydrogen or an alkyl group with1 to 4 carbon atoms, and B may be an alkyl group with 7 or more carbonatoms or an alicyclic hydrocarbon group with 6 to 12 carbon atoms, butthey are not limited thereto.

The second block (B) may include a polymerization unit (B1) of avinyl-based monomer of which a homopolymer has a solubility parameter ofless than 10 (cal/cm³)^(1/2).

For example, the vinyl-based monomer may be a compound represented bythe following Formula 3 or 4.

In Formula 3, X is a nitrogen atom or an oxygen atom, Y is a carbonylgroup or a single bond, R₃ and R₅ each independently represent hydrogenor an alkyl group, R₃ and R₅ are connected to each other to form analkylene group, and R₄ is an alkenyl group (but, when X is an oxygenatom, R₃ is not present);

In Formula 4, R₆, R₇ and R₈ each independently represent hydrogen or analkyl group, and R₉ is a cyano group or an aromatic substituent.

In Formula 3, when Y is a single bond, a structure in which there is noseparate atom at the part represented as Y, and R₅ and X are directlyconnected may be realized.

In Formula 3, R₄ may be, for example, a linear, branched or cyclicalkenyl group with 2 to 20, 2 to 16, 2 to 12, 2 to 8 or 2 to 4 carbonatoms, and may be optionally substituted or unsubstituted. Generally, avinyl group, an allyl group or the like may be used as the alkenylgroup.

In Formula 3, R₃ and R₅ may each independently represent hydrogen or alinear, branched or cyclic alkyl group with 1 to 20, 1 to 16, 1 to 12, 1to 8 or 1 to 4 carbon atoms, or may be connected to one another to forman alkylene group with 1 to 20, 2 to 16, 2 to 12 or 2 to 8 carbon atoms.In the above description, when R₃ and R₅ form an alkylene group, thecompound of Formula 3 may be a cyclic compound.

Examples of the vinyl-based monomer represented by Formula 3 or 4include a styrene-based monomer such as styrene or methyl styrene;acrylonitrile; an amide-based monomer such as an N-vinyl amide compound;an ester-based monomer such as a vinyl ester compound; or an ether-basedmonomer such as a vinyl ether compound or the like, but are not limitedthereto, and any vinyl-based monomer may be used as the vinyl-basedmonomer included as a polymerization unit in the amphiphilic polymeraccording to the present application without limitation as long as thevinyl-based monomer satisfies the aforementioned solubility parameter ofthe homopolymer.

Furthermore, the second block (B) includes a polymerization unit (B2) ofa polymerizable monomer having a functional group which is capable offorming a hydrogen bond.

The amphiphilic polymer according to the present application has thesecond block (B) including both the polymerization unit (B1) of anacrylic monomer or vinyl-based monomer and the polymerization unit (B2)of a polymerizable monomer having a functional group which is capable offorming a hydrogen bond, such that the capability of loading a targetdrug can be enhanced and a drug can be more suitably positioned at thecore of a micelle.

In the above description, the polymerizable monomer having a functionalgroup which is capable of forming a hydrogen bond may denote apolymerizable monomer other than the aforementioned acrylic monomer andvinyl-based monomer, having a functional group which is capable offorming a hydrogen bond.

In an embodiment, the functional group which is capable of forming ahydrogen bond of the polymerizable monomer may be, but is not limitedto, a hydroxyl group, an amine group, a nitro group, an amino group, animide group, an alkoxysilane group, a cyano group or the like, and isnot particularly limited as long as the functional group serves as anelectron donor which can increase the capability of loading a drug andhave a drug stably positioned at the core of a micelle by interactingwith —H, specifically, forming a hydrogen bond with —H in a drug, thatwill be described below.

Examples of the polymerizable monomer having an amine group include2-aminoethyl (meth)acrylate, 3-aminopropyl (meth)acrylate,N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl(meth)acrylate or the like, but are not limited thereto.

Examples of the polymerizable monomer having an alkoxysilane groupinclude vinyl alkoxysilanes, allyl alkoxysilanes, (meth)acryloxyalkylalkoxysilanes, vinyl acryloxy silanes, etc. Further, examples of the(meth)acryloxyalkyl alkoxysilanes include, 3-(meth)acryloxypropylmethyldimethoxy silane, 3-(meth)acryloxypropyl methyldiethoxysilane,3-(meth)acryloxypropyl trimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, (meth)acryloxymethyl triethoxysilane or(meth)acryloxymethyl tris(trimethylsiloxy) silane or the like, but arenot limited thereto.

Examples of the polymerizable monomer having a cyano group includecyanomethyl (meth)acrylate, cyanoethyl (meth)acrylate, or cyanopropyl(meth)acrylate, but are not limited thereto.

Such a polymerizable monomer capable of forming a hydrogen bond formsthe polymerization unit (B2) in the second block (B), and for example,the polymerization unit (B2) may be positioned at an outer side of thepolymer to act to load a drug.

Furthermore, the second block (B) may include the polymerization unit(B1) of an acrylic monomer or vinyl-based monomer and the polymerizationunit (B2) capable of forming a hydrogen bond of the polymerizablemonomer in a predetermined weight ratio.

For example, the weight ratio (B1:B2) of the polymerization unit (B1) ofan acrylic monomer or vinyl-based monomer of which a homopolymer has asolubility parameter of less than 10.0 (cal/cm³)^(1/2) to thepolymerization unit (B2) which has a polymerizable group capable offorming a hydrogen bond may be the same or different. For example, theweight ratio (B1:B2) may be in the range of 1:9 to 9:1. In anotherembodiment, the weight ratio (B1:B2) may be in the range of 2:8 to 8:2,3:7 to 7:3 or 4:6 to 6:4. When the weight ratio (B1:B2) is within thisrange, an amphiphilic polymer can effectively load a drug and be stablydispersed in an aqueous solution.

For example, the second block (B) may have a number average molecularweight in the range of 500 to 100,000. Within this range, the desiredhydrophobic property and capability of loading a drug can be secured.

Moreover, the block ratio (A:B) of the first block (A) and the secondblock (B) of the amphiphilic polymer according to the presentapplication may be the same or different.

In an embodiment, the block ratio (A:B) of the first block (A) and thesecond block (B) of the amphiphilic polymer according to the presentapplication may be different.

Specifically, the amphiphilic polymer according to the presentapplication may have the block ratio (A:B) of the first block (A) to thesecond block (B) controlled to 1:9 to 9:1. In the above description, theterm “block ratio (A:B)” refers to a weight ratio between the blocks.

In another embodiment, the block ratio (A:B) of the first block (A) tothe second block (B) may be 2:8 to 8:2, 3:7 to 7:3, or 4:6 to 6:4.

The amphiphilic polymer may have a number average molecular weight (Mn)in the range of 1,000 to 1,000,000.

Furthermore, the present application relates to a micelle including theaforementioned amphiphilic polymer.

In the present application, the term “micelle” may refer to a particleranging in size from several nanometers to tens of thousands ofnanometers in diameter and having a core-shell structure due toself-assembly properties of an amphiphilic polymer.

The micelle including the amphiphilic polymer according to the presentapplication may have excellent dispersion properties in water or oil aswell as high stability.

For example, the micelle may further include a drug encapsulated by anamphiphilic polymer.

In an embodiment, as shown in FIG. 1, the micelle according to thepresent application may have a structure with a drug and an amphiphilicpolymer encapsulating the drug. Furthermore, the amphiphilic polymerincludes a first block and second block, and any one of the secondblocks of the amphiphilic polymer may have a structure adjacent to adrug. In the above description, the term “encapsulation” refers to astructure in which an amphiphilic polymer surrounds a drug, and has thesame meaning as “loading” in the present application.

While drugs are generally insoluble, the drug according to the presentapplication is encapsulated by the amphiphilic polymer having both ahydrophobic region and a hydrophilic region, thus securing excellentdispersion properties of a drug in water or oil.

Furthermore, in the present application, a drug is encapsulated by theamphiphilic polymer with the second block (B) having the polymerizationunit (B2) which has a polymerizable group capable of forming a hydrogenbond, and thus a micelle having an excellent drug loading capability andsecuring stability can be provided.

Moreover, the micelle according to the present application has astructure with a drug encapsulated by the amphiphilic polymer which hasthe same or different block ratio (A:B) of the first block (A) to thesecond block (B), and thus can secure the superiority of theaforementioned dispersion properties.

For example, the drug included in the micelle of the present applicationmay include a biologically active substance, but is not particularlylimited.

In an embodiment, the biologically active substance may be insoluble.

The biologically active substance may be, for example, one or moreselected from the group consisting of genistein, daidzein, cucurbitacin,prangenidin or a derivative thereof; a polyphenol; or a mixture thereof.

As an example of the biologically active substance, the genistein,daidzein, cucurbitacin, prangenidin or the derivative thereof refers toa phenolic compound or a glycoside thereof contained in the soybean,that has a structure similar to estrogen which is a female hormone,exhibits an excellent antioxidative effect or the like, and is beingused in a wide range of applications such as skin care, anticancertherapy, etc.

Specifically, the isoflavone may be genistein or a glycoside of thegenistein, for example, acetyl genistein, malonyl genistein or the like,but is not limited thereto.

An isoflavone such as the genistein, daidzein, cucurbitacin, prangenidinor the derivative thereof is a phenolic compound, which includes —H inits molecule, and the —H in its molecule forms a hydrogen bond with thefunctional group capable of forming a hydrogen bond in the second block(B) of the amphiphilic polymer to improve stability of a drug positionedinside of a micelle.

The drug contained in the micelle may be included in the micelle at anamount by which the micelle can exhibit physiological activity whenprepared as a formulation.

In an embodiment, the content of the drug may be in the range of 1 to 60wt %, 1 to 50 wt %, 1 to 40 wt % or 1 to 20 wt % based on the totalweight of the micelle. When the content of the drug exceeds 60 wt %,effective loading cannot be performed, and the drug leaks out of themicelle and agglomerates in a crystalline form or is denatured.

Such a micelle may have, for example, an average particle size in therange of 1 to 10,000 nm. The average particle size of the micelle is avalue measured using a dynamic light scattering method, and may bewithin the range including the particle size of a single micelle ormicelle aggregates.

Furthermore, the present application relates to a composition includingthe aforementioned micelle.

In an embodiment, the present application relates to a composition forpreparing a particle, which includes the micelle containing theamphiphilic polymer.

The composition for preparing a particle according to the presentapplication includes a micelle formed due to self-assembly properties ofthe amphiphilic polymer. Moreover, the amphiphilic polymer forming thismicelle, for example, may encapsulate a drug.

For example, the micelle included in the composition for preparing aparticle may further contain a drug encapsulated by an amphiphilicpolymer.

Furthermore, the present application relates to a pharmaceutical orcosmetic composition, including the micelle which contains theamphiphilic polymer.

Specifically, the micelle included in the pharmaceutical or cosmeticcomposition may contain an amphiphilic polymer and a drug encapsulatedby the amphiphilic polymer.

In an embodiment, when the composition is a pharmaceutical composition,the drug in the micelle may be included in the composition in apharmaceutically acceptable form. Further, the pharmaceuticalcomposition may additionally include a pharmaceutically acceptablecarrier.

Moreover, the pharmaceutical composition may be formulated for oral ornon-oral administration.

In formulating the pharmaceutical composition, commonly used excipientsor diluents such as fillers, bulking agents, binders, wetting agents,disintegrating agents, and surfactants may be used.

In an embodiment, solid formulations for oral administration includetablet, bolus, powder, granule, capsule and the like, and the solidformulation may be prepared by mixing one or more of the activecomponents with at least one excipient such as starch, calciumcarbonate, sucrose, lactose, gelatin, etc.

In an embodiment, liquid formulations for oral administration aresuspensions, solutions, emulsions and syrups, and the aforementionedformulations may contain various excipients such as wetting agents,sweeteners, aromatics, preservatives or the like in addition togenerally used simple diluents such as water and liquid paraffin.Examples of formulations for parenteral administration includesterilized aqueous solutions, water-insoluble excipients, suspensions,emulsions, lyophilized preparations and suppositories.

The pharmaceutical composition may be formulated in any type suitablefor pharmaceutical preparations, including oral preparations such aspowder, granule, tablet, capsule, suspension, emulsion, syrup, aerosolor the like, external preparations such as ointment, cream or the like,suppository or sterilized solution for injection, etc. using a commonmethod.

In another embodiment, the composition may be, for example, a cosmeticcomposition that may be contained in an external preparation for theskin, having formulations such as skin lotion, skin softener, skintoner, astringent, nutrition toner, nutrition cream, cleansing foam,essence, pack, etc.

The cosmetic composition and external preparation for the skin mayfurther include known additive components, for example, including apowder base or carrier such as a binder, a disintegrant, an excipient, alubricant or the like, an oily base or carrier such as animal andvegetable oils, waxes, vaseline, paraffin oil, silicone oil, a higherfatty acid ester, a higher fatty acid or the like, an aqueous base orcarrier such as a gel base including a xanthan gum or the like,preservatives, chelating agents, antioxidants, refreshing agents,stabilizers, fluidizing agents, shear-thickening agents, bufferingagents, dispersing agents, absorbents, moisturizing agents, wettingagents, desiccants, antistatic agents or other resins such as apolyamide-based resin, an olefin-based resin such as a hydrogenatedpolybutene, etc.

The pharmaceutical composition or cosmetic composition may be in theform of a water-in-oil or oil-in-water emulsion.

For example, the micelle in the composition may form aggregates. Themicelle aggregates may be formed due to a van der Waals' force betweenthe hydrophobic regions. For example, the micelle aggregates may have asize in the range of 10 to 10,000 nm.

Further, the present application relates to a method of preparing theaforementioned amphiphilic polymer.

That is, the preparation method according to the present applicationincludes polymerizing a polymer which forms a first block (A) with anacrylic monomer or vinyl-based monomer of which a homopolymer has asolubility parameter of less than 10.0 (cal/cm³)^(1/2).

Specifically, in the method of preparing the amphiphilic polymeraccording to the present application, an example of a method ofpolymerizing the polymer which forms a first block (A) with theaforementioned monomer may be a living radical polymerization method,for example, an atom transfer radical polymerization (ATRP) method toeffectively achieve narrow molecular weight distribution and a desiredmolecular weight, but is not particularly limited thereto.

More specifically, the amphiphilic polymer according to the presentapplication may be prepared by reacting the polymer which forms thefirst block (A) and includes a halogen atom with a transition metalcomplex catalyst to generate radicals for receiving electrons at adouble bond site of an acrylic monomer or vinyl-based monomer forforming the second block, and forming second block (B) with apolymerization unit (B1) of an acrylic monomer or vinyl-based monomerand a polymerization unit (B2) having a functional group which iscapable of forming a hydrogen bond, but is not limited thereto.

For example, the polymer which forms the first block is a polymer thatdoes or does not include a halogen atom, and has a solubility parameterof 10 (cal/cm³)^(1/2) or more. When a polymer for forming the firstblock that does not include a halogen atom is used, a step of preparingan initiator for ATRP by the reaction with a compound including ahalogen atom may be further included.

Furthermore, the present application relates to a method of preparing amicelle, which includes mixing a drug with the amphiphilic polymerprepared as above.

A method for mixing an amphiphilic polymer and a drug to prepare themicelle is not particularly limited, and for example, the method mayinclude dissolving a predetermined organic solvent such as ethanol orthe like with the amphiphilic polymer and mixing the solution thusprepared with a solution containing a drug.

Furthermore, a process of removing the solvent may be included as asubsequent process after the aforementioned process, but the presentapplication is not limited thereto, and the method may additionallyinvolve a known process between each of the processes or as a subsequentprocess.

A temperature in the process of removing the solvent is differentaccording to the boiling point of each solvent, and for example, thesolvent may be removed at a temperature of 50° C. or more, but thepresent application is not limited thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent to those of ordinary skill in theart by describing in detail exemplary embodiments thereof with referenceto the accompanying drawings, in which:

FIG. 1 is a schematic view of a micelle including the amphiphilicpolymer according to the present application;

FIG. 2 shows images for determining precipitation of amphiphilicpolymers according to examples and comparative examples and drugsencapsulated by the amphiphilic polymers; and

FIG. 3 is a schematic view of a Franz cell for a percutaneous absorptiontest.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the present application will be described in detail withreference to examples, but the following examples are only exampleswithin the gist of the present application. Meanwhile, it is apparent tothose skilled in the art that the present application is not limited toprocess conditions proposed by the following examples but may bearbitrarily selected within a range required to achieve the objects ofthe present application.

EXAMPLE 1 Preparation of Amphiphilic Polymer P1

After a polyethyleneglycol monomethyl ether polymer (molecular weight:

5000, purchased from Sigma-Aldrich Co. Llc) forming a first block wasdissolved in dichloromethane at a concentration of 30%, 3 equivalentweights of triethylamine and 2 equivalent weights of 2-bromo isobutyrylbromide were introduced with respect to a —OH group to perform areaction, thereby preparing an initiator for ATRP. Then, a process ofprecipitation and loading of the initiator in a diethyl ether solventwas repeated twice and drying was performed to remove impurities andobtain a polyethylene glycol polymer at bromine end groups. 100 parts byweight of the polyethylene glycol polymer with bromine end groups thusobtained was dissolved in 250 parts by weight of an anisole-containingreaction solvent in a flask, methyl methacrylate with a solubilityparameter of 9.5 (cal/cm³)^(1/2)) and N,N-dimethylarninoethylmethacrylate with a solubility parameter of 9.6 (cal/cm³)^(1/2) wereadded thereto in the weight ratio of 80:20, and a flask was sealed witha rubber stopper. Thereafter, nitrogen purging and stirring were carriedout at room temperature for 30 minutes to remove dissolved oxygen, theflask was dipped in an oil bath with a temperature set to 60° C., and acopper (II) bromide complex and a catalytic reducing agent wereintroduced thereinto to perform a reaction. When a desired molecularweight was obtained, the reaction was completed, thereby preparing anamphiphilic polymer P1 with a B-A-B triblock structure. The molecularweight and the ratio B:A:B of each block of the triblock of theamphiphilic polymer P1 are shown below in Table 1.

EXAMPLE 2 Preparation of Amphiphilic Polymer P2

An amphiphilic polymer P2 with a triblock structure (B-A-B) was preparedin the same manner as in Example 1 except that methyl methacrylate witha solubility parameter of 9.5 (cal/cm³)^(1/2)) andN,N-dimethylaminoethyl methacrylate with a solubility parameter of 9.6(cal/cm³)^(1/2) were added thereto in the weight ratio of 60:40. Themolecular weight, the ratio B:A:B of each block of the triblock and theweight ratio B1:B2 of polymerization units in the second block (B) ofthe amphiphilic polymer P2 are shown below in Table 1.

COMPARATIVE EXAMPLE 1

A polycaprolactone (B)-polyethylene glycol (A)-polycaprolactone (B)copolymer P4, in which a polycaprolactone with a solubility parameter ofapproximately 10 (cal/cm³)^(1/2) which is a polyester-based polymer wasused, was prepared by the following method.

Specifically, the synthesis was conducted through ring-openingpolymerization with a polyethylene glycol polymer (molecular weight:2000, purchased from Daejung Chemical & Metal Co.) as an initiator.Stannous 2-ethyl-hexanoate (Sn(Oct)₂) was used as a catalyst. Thepolyethylene glycol and Sn(Oct)₂ were dried at 110° C. under vacuumconditions for 4 hours in a 2-neck round flask to eliminate moisture,and a reactor was cooled to room temperature. ε-Caprolactone was addedin the same amount as polyethyleneglycol monoethyl ether to the reactorin a nitrogen atmosphere and vacuum-dried at 60° C. for 1 hour. Thereactor was gradually cooled to 130° C. in a nitrogen atmosphere toperform a reaction for 18 hours, and cooled to room temperature again tocomplete the reaction. Methylene chloride was added to the reactorcooled to room temperature to dissolve a reactant, and an excess amountof cold ethyl ether was gradually added to precipitate a copolymer. Theprecipitated block copolymer was filtered and vacuum-dried at 40° C. for48 hours to finally obtain a polycaprolactone (B)-polyethylene glycol(A)-polycaprolactone (B) copolymer P4.

COMPARATIVE EXAMPLE 2 Preparation of Amphiphilic Polymer P4

The amphiphilic polymer P4 was prepared in the same manner as inComparative Example 1 except that the amount of added ε-caprolactone wastwice the amount of polyethyleneglycol monoethyl ether during thesynthesis of a polyethylene glycol (A)-polycaprolactone (B) copolymer inwhich a polycaprolactone with a solubility parameter of approximately 10(cal/cm³)^(1/2) which is a polyester-based polymer was used.

EXPERIMENTAL EXAMPLE 1 Evaluation of Block Ratio B:A:B of PreparedAmphiphilic Polymer

The block ratio of the prepared amphiphilic polymers P1 to P5 wasevaluated by the following method and the results are shown in Table 1.

Specifically, the polymer solution from which the catalyst wascompletely removed underwent a purification process to be solidified,and the block ratio of the amphiphilic polymer was determined by 1H NMRanalysis. The purification of the polymer solution was carried out byhaving the polymer solution pass through an alumina column to eliminatea copper complex catalyst, and adding the polymer solution dropwise intoan excess amount of diethyl ether with stirring to remove the remainingmonomer to be solidified. The solidified polymer was dried in a vacuumoven for 24 hours. The amphiphilic polymer purified by theaforementioned method was dissolved in a CDCl₃ solvent and measuredusing 1H-NMR analysis equipment. In the case of Examples 1 and 2 andComparative Examples 1 and 2, as the analysis result, a 1H peak derivedfrom CH₂═C(CH₃)— at double-bond end groups was not deteiniined, fromwhich it can be seen that no unreacted monomer existed. Moreover, 3Hpeaks derived from —OCH₃ of ethylene glycol block end groups wereconfirmed at around 3.2 ppm, and thus the ratio and molecular weight ofeach copolymer block was calculated based on this. Approximately 450 ofH peaks (4H×113 repeat units) derived from —CH₂CH₂O— of ethylene glycolformed of the polymer were shown in a 3.6 to 3.8 ppm region, and in thecase of Examples 1 and 2, 3H peaks derived from —CH₃ adjacent to a mainchain of methyl methacrylate formed of the polymer were shown in a 3.5to 3.6 ppm region, 2H peaks derived from —OCH₂— adjacent to —COO— of aside chain of dimethylaminoethyl methacrylate formed of the polymer wereshown in a 4.0 to 4.2 ppm region, and thus the content of eachconstituent monomer was calculated as a mass fraction through the arearatio thereof. In the case of Comparative Examples 1 and 2, 2H peaksderived from the first —CH₂— from the right of —CO—in—(CO—CH₂CH₂CH₂CH₂CH₂—O—)_(n) which is a chain of caprolactone formedof the polymer were shown in a 2.3 to 2.4 ppm region, and thus themolecular weight was confirmed by the area of 3H peaks derived from—OCH₃ of ethylene glycol block end groups and the area of 2H peaksderived from the first —CH₂— from the right of —CO— of caprolactone.

TABLE 1 Molecular weight Weight ratio (B1:B2) (Mn, second Block ofpolymerization block:first ratio units of second block block:secondblock) (A:B:A) (B) (B1:B2)^(a) Example 1 11,000 (5,000:6,000) 4.55:5.4580:20 Example 2 11,000 (5,000:6,000) 4.55:5.45 60:40 Comparative  9,900(5,000:4,900) 5.05:4.95 — Example 1 Comparative 14,700 (5,000:9,700)0.34:0.66 — Example 2 ^(a)Mass ratio of methyl methacrylate(B1):N,N-dimethylaminoethyl methacrylate (B2)

EXPERIMENTAL EXAMPLE 2 Preparation of Micelle and Determination ofDissolved Concentration of Drug

Genistein which is an insoluble substance was loaded using thesynthesized amphiphilic polymers P1 to P5. First, a solution obtained bydissolving 10 g of the amphiphilic polymer in 30 mL of ethanol was mixedwith a solution obtained by dissolving 20 g of dipropylene glycol (DPG)in 2 g of genistein. After the mixed solution was introduced into 100 mLof a 0.5% polyvinyl alcohol aqueous solution with stirring, theremaining ethanol was eliminated using a rotary evaporator to prepare asolution in which the content of genistein was 2%. The prepared solutionwas diluted with 10 times as much distilled water and stored at roomtemperature (25° C.) for 7 days to determine whether property changes ofthe solution occurred over time using an optical microscope, and theresults are shown in FIG. 2. Furthermore, after the solution wasfiltered using a syringe filter with a pore size of 1 μm to eliminatethe precipitated genistein, the content of genistein loaded in anamphiphilic polymer micelle particle was measured by liquidchromatography (HPLC). The drug loading capacity and drug loadingefficiency of the amphiphilic polymer were calculated according to thefollowing equations, and the particle size of the amphiphilic polymermicelle in which a drug was loaded was measured using Zetasizer 3000manufactured by Malvern Instruments, Inc.

$\begin{matrix}{{{Drug}\mspace{14mu} {loading}\mspace{14mu} {capacity}} = {\frac{{Amount}\mspace{14mu} {of}\mspace{14mu} {impregnated}\mspace{14mu} {drug}}{\begin{matrix}{{{Amount}\mspace{14mu} {of}\mspace{14mu} {impregnated}\mspace{14mu} {drug}} +} \\{{Content}\mspace{14mu} {of}\mspace{14mu} {block}\mspace{14mu} {copolymer}}\end{matrix}}s\; 100(\%)}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack \\{{{Drug}\mspace{14mu} {loading}\mspace{14mu} {efficiency}} = {\frac{{Amount}\mspace{14mu} {of}\mspace{14mu} {impregnated}\mspace{14mu} {drug}}{{Initial}\mspace{14mu} {drug}\mspace{14mu} {dose}}s\; 100(\%)}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

The results of measuring the particle size of the micelle and theresulting drug loading capacity and drug loading efficiency of themicelle are shown in the following Table 2.

TABLE 2 Comparative Comparative Example 1 Example 2 Example 1 Example 2Particle size (nm) 125 135 100 150 Drug loading 10.7 16.1 1.2 1.8capacity (%) Drug loading 60 96 6 9 efficiency (%)

EXPERIMENTAL EXAMPLE 3 Percutaneous Absorption Test

The percutaneous absorption of genistein of the amphiphilic polymersolution in which genistein was loaded and which was prepared as abovewas evaluated using porcine skin (2×2 cm, thickness: 1000 μm) and aFranz diffusion cell. A phosphate buffered saline (PBS) solutioncontaining 30 wt % of dipropylene glycol (DPG) was used as an aqueoussolution (acceptor solution) to maintain a sink condition with respectto genistein. 0.2 g of the amphiphilic polymer solution on whichgenistein was loaded was loaded in a Franz diffusion cell on which theporcine skin was mounted, and the test was performed at 32° C. similarto a skin temperature for 24 hours. Skin tissue into which genistein wasabsorbed was pulverized and extracted to analyze the content ofgenistein absorbed into the skin tissue and the content of genisteinabsorbed into the acceptor solution through HPLC, and the results areshown in Table 3.

TABLE 3 Comparative Comparative Example 1 Example 2 Example 1 Example 2Skin penetration 1.85 3.70 0.22 0.35 amount (μg/cm²) Skin penetration1.05 2.10 0.13 0.20 ratio (%)

The present application can provide an amphiphilic polymer that caneffectively encapsulate a drug and have excellent dispersion propertiesin an aqueous solution, and a method of preparing the same.

Furthermore, the present application can provide a micelle that iseffectively dispersed in water or oil, and capable of exhibitingexcellent percutaneous absorption properties when prepared as aformulation, and a composition including the same.

The above description of the present invention is merely an example, andit will be apparent to those skilled in the art that variousmodifications can be made to the above-described exemplary embodimentsof the present invention without departing from the spirit or scope ofthe invention. Thus, the above-described embodiments of the presentinvention are intended merely to be examples in all aspects and thepresent invention is not limited thereto.

1. An amphiphilic polymer, comprising: a first block (A); and a secondblock (B) which is phase-separated from the first block (A) and includesa polymerization unit (B1) of an acrylic monomer or vinyl-based monomerof which a homopolymer has a solubility parameter of less than 10.0(cal/cm³)^(1/2) and a polymerization unit (B2) of a polymerizablemonomer having a functional group which is capable of forming a hydrogenbond, wherein a weight ratio (B1:B2) of the polymerization unit (B1) ofan acrylic monomer or vinyl-based monomer of which a homopolymer has asolubility parameter of less than 10.0 (cal/cm³)^(1/2) to thepolymerization unit (B2) of a polymerizable monomer having a functionalgroup which is capable of forming a hydrogen bond in the second block(B) is in a range of 1:9 to 9:1.
 2. The amphiphilic polymer of claim 1,wherein the first block (A) includes a polymer having a solubilityparameter of 10.0 (cal/cm³)^(1/2) or more.
 3. The amphiphilic polymer ofclaim 1, wherein the first block (A) is one or more selected from thegroup consisting of a polyethylene glycol, a polyethyleneglycol-propylene glycol copolymer, a polyvinylpyrrolidone and apolyethyleneimine.
 4. The amphiphilic polymer of claim 1, wherein theacrylic monomer is a compound represented by the following Formula 1 or2:

where, in Formulas 1 and 2, Q is hydrogen or an alkyl group, in Formula1, B is a linear or branched alkyl group with one or more carbon atoms,an alicyclic hydrocarbon group, an aromatic substituent or a carboxylgroup, and in Formula 2, R₁ and R₂ each independently representhydrogen, a linear or branched alkyl group with one or more carbonatoms, an alicyclic hydrocarbon group, or an aromatic substituent. 5.The amphiphilic polymer of claim 4, wherein, in Formula 1, Q is hydrogenor an alkyl group with 1 to 4 carbon atoms, and B is an alkyl group withone or more carbon atoms or an alicyclic hydrocarbon group with 6 to 12carbon atoms.
 6. The amphiphilic polymer of claim 1, wherein thevinyl-based monomer is a compound represented by the following Formula 3or 4:

where, in Formula 3, X is a nitrogen atom or an oxygen atom, Y is acarbonyl group or a single bond, R₃ and R₅ each independently representhydrogen or an alkyl group, R₃ and R₅ are connected to each other toform an alkylene group, and R₄ is an alkenyl group (but, when X is anoxygen atom, R₃ is not present);

where, in Formula 4, R₆, R₇ and R₈ each independently represent hydrogenor an alkyl group, and R₉ is a cyano group or an aromatic substituent.7. The amphiphilic polymer of claim 1, wherein the functional group is ahydroxyl group, an amine group, a nitro group, an amino group, an imidegroup, an alkoxysilane group or a cyano group.
 8. The amphiphilicpolymer of claim 1, wherein a block ratio (A:B) of the first block (A)and the second block (B) is different.
 9. The amphiphilic polymer ofclaim 8, wherein a block ratio (A:B) of the first block (A) to thesecond block (B) is in a range of 1:9 to 9:1.
 10. The amphiphilicpolymer of claim 8, wherein a block ratio (A:B) of the first block (A)to the second block (B) is in a range of 3:7 to 7:3.
 11. A micellecomprising the amphiphilic polymer of claim
 1. 12. The micelle of claim11, further comprising a drug encapsulated by the amphiphilic polymer,wherein a second block of the amphiphilic polymer is adjacent to thedrug.
 13. (canceled)
 14. The micelle of claim 11, wherein an averageparticle size is in a range of 1 to 10,000 nm.
 15. The micelle of claim12, wherein the drug includes an insoluble biologically activesubstance.
 16. (canceled)
 17. The micelle of claim 14, wherein theinsoluble biologically active substance is one or more selected from thegroup consisting of genistein, daidzein, cucurbitacin, prangenidin or aderivative thereof; a polyphenol; and a mixture thereof.
 18. Acomposition for preparing a particle, comprising the micelle of claim11, wherein the micelle preferably further includes a drug encapsulatedby the amphiphilic polymer.
 19. (canceled)
 20. A pharmaceutical orcosmetic composition, comprising the micelle of claim
 11. 21. Thepharmaceutical or cosmetic composition of claim 20, wherein the micellefurther includes a drug encapsulated by the amphiphilic polymer.
 22. Thepharmaceutical or cosmetic composition of claim 21, which is in the formof water-in-oil or oil-in-water emulsion.
 23. A method of preparing theamphiphilic polymer of claim 1 comprising a step of polymerizing apolymer which forms a first block (A) with an acrylic monomer orvinyl-based monomer of which a homopolymer having a solubility parameterof less than 10.0 (cal/cm³)^(1/2) and a polymerizable monomer having afunctional group which is capable of forming a hydrogen bond.